In current wireless communication systems, there are problems of loss of data or data dropout of wireless medical telemetry services caused by fading. Fading refers to the deviation in the attenuation that a carrier-modulated RF signal experiences over a propagation media. The fades usually result from multipath propagation, (where different paths of the same signal combining in a destructive manner), or shadowing, (where obstacles obstruct the wave propagation). Fading models can be used to describe how fades might occur, but signal fading is a random phenomenon and cannot be eliminated from any wireless communication system.
Thus, it is desirable to reduce the probability that a signal fade will impact the performance of a wireless system. By reducing the probability that a fade causes a loss of data or data dropout in the system, the reliability of the wireless communication system is improved.